Messages in this thread | | | Date | Wed, 30 Nov 2022 15:50:55 +0100 | From | Thomas Weißschuh <> | Subject | Re: [PATCH v2 1/3] printk: introduce new macros pr_<level>_cont() |
| |
On 2022-11-30 14:59+0100, Petr Mladek wrote: > On Fri 2022-11-25 21:33:40, Thomas Weißschuh wrote: >> On 2022-11-25 12:18-0800, Joe Perches wrote: >>> On Fri, 2022-11-25 at 20:09 +0100, Thomas Weißschuh wrote: >>>> These macros emit continuation messages with explicit levels. >>>> In case the continuation is logged separately from the original message >>>> it will retain its level instead of falling back to KERN_DEFAULT. >>>> >>>> This remedies the issue that logs filtered by level contain stray >>>> continuation messages without context. >>>> >>>> --- a/include/linux/printk.h >>>> +++ b/include/linux/printk.h >>>> @@ -701,6 +703,27 @@ do { \ >>>> no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) >>>> #endif >>>> >>>> +/* >>>> + * Print a continuation message with level. In case the continuation is split >>>> + * from the main message it preserves the level. >>>> + */ >>>> + >>>> +#define pr_emerg_cont(fmt, ...) \ >>>> + printk(KERN_EMERG KERN_CONT pr_fmt(fmt), ##__VA_ARGS__) >>> >>> Aren't this rather backwards? >>> KERN_CONT KERN_<LEVEL> seems to make more sense to me. >> >> If nobody else disagrees I'll do this for v3. > > I slightly prefer the way how it is now. IMHO, it makes it easier > to check the related levels in /sys/kernel/debug/printk/index/vmlinux [*]: > > <6> kernel/power/process.c:227 thaw_kernel_threads "Restarting kernel threads ... " > <6,c> kernel/power/process.c:218 thaw_processes "done.\n" > <6> kernel/power/process.c:197 thaw_processes "Restarting tasks ... " > <6,c> kernel/power/process.c:176 freeze_kernel_threads "\n" > <6,c> kernel/power/process.c:174 freeze_kernel_threads "done." > <6> kernel/power/process.c:169 freeze_kernel_threads "Freezing remaining freezable tasks ... " > <6,c> kernel/power/process.c:140 freeze_processes "\n" > <6,c> kernel/power/process.c:138 freeze_processes "done." > <6> kernel/power/process.c:133 freeze_processes "Freezing user space processes ... " > <6,c> kernel/power/process.c:105 try_to_freeze_tasks "(elapsed %d.%03d seconds) "
I did not test it (will do so later) but it seems to me that the code in kernel/printk/index.c should do this correctly in either case. At least it tries to:
if (flags & LOG_CONT) { /* * LOGLEVEL_DEFAULT here means "use the same level as the * message we're continuing from", not the default message * loglevel, so don't display it as such. */ if (level == LOGLEVEL_DEFAULT) seq_puts(s, "<c>"); else seq_printf(s, "<%d,c>", level); } else seq_printf(s, "<%d>", level); } }
I'll try to validate it.
If it doesn't work it may make more sense to fix the index file generation. What do you think
> That said, I do not want to fight over it. It is hidden behind the > API. The only really visible place is the printk index. > > [*] The index is available only when CONFIG_PRINTK_INDEX is enabled. > > Best Regards, > Petr
Thomas
| |